1. Field of the Invention
The present invention relates to a melody generating apparatus and method, and a machine readable medium containing program instructions for realizing such an apparatus and a method, and more particularly to a melody generating apparatus and method in which, as key information and chord information are given, an available note scale is determined for a given chord in a given key and notes in the determined available note scale are sequentially employed to generate a melody, which will feel natural from a musical point of view including notes suitable for even nondiatonic chords. The invention is applicable in various kinds of electronic musical apparatuses such as an electronic musical instrument, an automatic music composing apparatus, and a computer-system-configured music composing apparatus.
2. Description of the Prior Art
Among various types of melody generating apparatuses known heretofore, there is a type of melody generating apparatus in which a key for an entire melody to be composed (i.e. generated) is designated or keys for respective fractions of a melody to be composed are designated, and a pitch template (a pitch variation pattern), a pitch for the first note in the phrase, a pitch for the last note in the phrase, etc are also designated for each of the phrases constructing a melody, and then notes are selectively employed in sequence for each phrase from among the scale notes of the key for the phrase and in such a fashion that the selected notes exhibit a melody motion which meets the designated pitch variation pattern. Such an example is disclosed in unexamined Japanese patent publication No. Hei 9-50287.
Another known type of melody generating apparatus is the one in which a chord progression for a melody to be composed is given and then a key is determined for each chord span based on the chord designated for that span and the chord(s) of the preceding span(s), and notes are selectively picked up from the musical scale of the determined key to be aligned in a time sequence, thereby to generate a melody. Such an example is disclosed in issued Japanese patent publication No. 2,615,721.
With the apparatus of the above first type, i.e. a key designation type, upon designation of a key or keys, there will be generated a melody which matches the designated key. However, a melody which matches a chord or chords arbitrarily designated by the operator may not always be generated.
On the other hand, with the apparatus of the above second type, upon designation of desired chords, there will be generated a melody which matches such designated chords. The melody, however, is constructed using only the scale notes of the key as detected from the designated chord, and therefore a melody produced based on a diatonic chord (a chord constituted by the notes included in the scale notes of the key) will be good and agreeable with the chord, but a melody generated based on a nondiatonic chord (a chord having at least a note which is not included in the scale of the key in addition to a note or notes in the scale of the key) will not be so well mingled with the chord, and consequently it will be hard to generate a natural pleasing melody which is adequate for the chord.